Peters



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N. B CLARK & F. B; KING.

STEAM BOILER.

Patented Feb.

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(No Model.)

N; B. CLARK 82 F. B. KING.

STEAM BOILER.

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3 Sheets'Sheet 3.

N. B. CLARK & F. B. KING.

(No Model.)

STEAM BOILER.

No. 421,387. Patented Feb. 18, 1890.

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N. PETERS, Phnfio-LlKhogF-lphel: Washingtnn. [1.13.

UNITED STATES PATENT OFFICE.

NATHAN B. CLARK, OF UNITED STATES NAVY, AND FRANK B. KING, OFWVASI-IINGTON, DISTRICT OF COLUMBIA.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 421,387, dated February18, 18 90. Application filed June 8, 1889. Serial No. 313,548. (Nomodel.)

I all whom, it may concern:

Be it known that we, NATHAN B. CLARK, United States Navy, and FRANK B.KING, both residing at Washington, in the District of Columbia, haveinvented certain new and useful Improvements in Steam-Boilers, of whichthe following is a specification, reference being had therein to theaccompanying drawings.

1o This invention relates to steam-boilers, an d is especially intendedfor marine boilers, although applicable to other uses.

The object of the invention is to producea boiler in which the partsshall be strong and [5 somewhat elastic, the circulation rapid, and

the casing exposed to the fire shall be largely protected bywater-tubes.

Figure 1 is a top plan with part broken away to show a longitudinalsection on the level of the water-tubes, which are partly omitted. Fig.2 is a side elevation with part of easing removed. Fig. 3 is across-section about on the line of one of the water-pipes forminggrate-supports, say on line y y, Fig. 4. Fig. 3 is an enlarged detail ofFig. 3. Fig. 4 is a longitudinal section about on line w m, Fig. 3. Fig.5 is a broken sectional detailof the manifold and side casing. Fig. 6 isa broken inner side elevation of manifold and casing. Fig. 7 is a brokendetail of one of the connectingtubes and ties, partly in section. Fig. 8is a similar side view of de tail, Fig. 7. Fig. 9 is a brokencross-sectional detail of central tie -plate and fastenings. Fig. 10 isan enlarged horizontal section of downcast conduit protecting tubes andcasing on lines A B, Fig. 11. Fig. 11 is a section about on line z c,Fig. 10.

The shell of the boiler is composed of continuous convoluted sheets ofmetal, the convolutions consisting of arches or curves of differentradii, there being a reverse curve of small radii between each twoarchesof large radii. Tie-braces are attached tangentially to the large arcs.The small arcs may be very small, and need not necessarily conform to acircle.

The numeral 1 indicates the shell-plate of the intermediate topsections, of which any convenient number may be employed.

2 2 denote the side shell-plates.

The plates forming the top shell may be integral or not. The plates atthe junction of the arches 1 1 are secured to a tie-plate 3, thejoint-pieces being stayed or strengthened by angleplates 4 4, held byrivets or bolts in any usual manner. The-front and rear end walls of thearched portions of the shell are formed of convolute plates 5 5, asindicated in Figs. 1 and 2 of the drawings. The tieplate 3 is held tothe tube-sheet 7 at the lower edge by angle-pieces 8 8. The bottommember of the boiler is somewhat similar to the top member, havingarches or convolutions in reverse direction and having the edges of thearches Iconnected to the bottom tubesheet 17. The space between thetube-sheets 7 and 17 is pretty well filled with vertical water-tubes 11.A plate 13 below the tieplate 3 connects the tube-sheet 7 to the bottommember of the boiler. The lower edge of plate 13 is riveted or otherwisefastened to the upturned edges of the arched or convolute plates 21,which form the shell of the lower member of the boiler. (See Fig. 9.)

The tie-plate and casing at the sides of the space filled by tubes 11are substantially like the tie-plate 13, but protected on the innersurface only. The plate 3 is preferably perforated, and plate 13 mayalso be perforated for lightness. Plate 13 is protected by asbestus,soapstone, or other refractory slabs or sheets 14, and the water-tubes11 next these protective sheets serve to protect them also from theintense heat of the flame which passes between the tubes 11. The edgesof the lower tube-sheet 17 are corrugated at 22, and riveted to thearch-plates below the corrugations to permit. a slight elasticity anddifference of expansion in the parts. The space 23 within thecorrugations may be filled with asbestus or other refractory packing,and the space 21 between the edges of the arch-platesmay be similarlyfilled, the latter filling being retained by binding-strips 25, securedto the arches. The side plates 2 and the central shell-plates 1, Fig. 3,are riveted or otherwise fastened to tie-plates 33 one at each side ofthe entering angle or curve. Tie-plates 33 reach down nearly to thetube-sheet 7. The lower edges of the plates 33 are bolted or otherwisefastened to flanges 34 on open thimbles 35, which thimbles have internalscrew-threads. Tie-tubes 36 extend from the upper t-himbles 35 to acorresponding set of thimbles 35 to which the upturned edges 21 of thelower arched plates 21 are bolted or riveted. (See Figs. 7 and S.) Theconvolute plates are secured at the convolutions by angle-plates 21 tothe thimbles. Thus the plates constituting; the arches may be of anywidth which is a multiple of an arch, the edges of sheets being securedand the convolutions braced. the tubesheets 7 and 17, through which thetie-tubes pass, may be stopped by packing bushes with grommets 37, whichengage the external screw-threaded portion of the tie-tubes 36 and holdthe tube-sheets fast to the tie-tubes. As the upper arched plates 2throw a heavy stress on the tube-plate 7 ,itis advisable that this tubebe thicker than plate 17. This plate 7 forms a transverse tie betweenthe sides of the boiler. The upper arched sections of the boiler areconnected to the lower reversed sections, at the rear of the fire-box,by downcast conduits 23, which may connectwith a slight offset at therear of the tube-sheet 7. The downcast conduits 23 extend below thelevel of the lower arches 21, and each downcast connects with acorresponding lower arch by a conduit-1S, which terminates inside thedowncast in a scoop or spoon 19. The downcasts 23 are of ample capacityand convey large volumes of water from the upper to the lower arches,the

scoops 19 tending to deflect the downwardlymoving current into the lowerarches.

As the side of the downcasts 23 toward the fire-box will be exposed tointense heat, there will be a tendency to the formation of an upwardcurrent of mixed steam and water on this face of the downcasts. Curvedshields 24 are therefore placed in the downcasts near this face, formingcurved chambers 25, up

I which the steam and water may pass, as

shown in Figs. 10 and 11. These plates 24 are curved forward at theupper ends to'catch the steam, and pipes 26 extend upward to conveysteam up into the steam-space of the boiler. The downcasts 23 areconnected together below the pipes 18 by cross-pipes 28, .and below theconduits may form sedimenttraps. The cross-pipes 28 are connected to thetube-sheet 7 by tubes 41, Figs. 10 and 11.

1 These tubes serve as supports for the refrac- The openings throughheat of such a furnace as We employif fully exposed to the flame, it isfound that a protection by water-pipes covering a part of the surfaceadds greatly to the durability. Thus the downcasts 23 and water-tubes 41protect the casing 44 45 46 quite efficiently. (See Figs. 10 and 11.)Should the length of' the arches be great, the front of the top membermay be connected to the bottom member by a large downcast 20, extendingfrom tubesheet 7 to tube-sheet 17. The theory of upward circulationthrough small water-tubes and downward circulation through large tubesis well understood.

The direction of the hot gases is from the furnace 47 backward under thebottom boiler member to the downcasts 23, then upward boiler, pipes 51extend forward to the front end of the furnace to supply water to thevertical tubes of the manifold. (See Fig. '2.) These pipes should taper,as the water-supply will be proportioned to the distance from thedowncast, and a convenient construction is shown in Figs. 5 and 6, wherethe bottom and sides of the pipev are shown composed of a horseshoecurved plate 52 and the top of a flat plate 53, flanged downward, thejoints being riveted.

The lower boiler member has branches 60 leading to manifold boxes 61about on a level with the top of the furnace and parallel with pipes 51.and can be separately replaced. The rear box 61% is connected to the topmember of the boiler instead of the bottom member. The boxes 61 are madeof short lengths, with The boxes 61 are short sections single points ofattachment, in order to 'overcome the effects of expansion andcontraction.

Each manifold box 61 has a number of water-tubes 62 connected to pipe'51, these water-tubes forming the inner sidewall of the furnace. Thebox 61 .should be long enough to contain about six of these tubes 62,andat the top of the box, over each tube, there is a hole covered by acap 63, held down by a suitable clamp 64. The caps 63 may be removed andthe tubes 62 withdrawn through the opening, the tubes being secured orexpanded into place in usual manner.

Outside the tubes 62 we place plates of soapstone, fire-brick, or otherrefractory material 54, then a packing of asbestus or similar material55, and then a covering of corrugated metallic plates 56, this outercovering being supported by angle-plates 57 and removable fastenings 58.may be closed by a refractory covering 59.

The side walls of the tube-space filled with The space between tubes 60tubes 11 are covered by light open plates 73,

ted lines, Fig. 4, thus giving access to the upper ends of tubes 11 forcleaning or replacement. It will thus appear that the skeleton of thefurnace is composed of the grate, vertical Water-tubes at the sides, andnearly ver- ,removed and readily replaced.

tical downcasts at the rear, the top of the furnace being the arches ofthe lower boiler member. The heat from the furnace passes backward, thenupward between pipes 18, then forward among water-tubes 11 and 36, andso to the uptake. heavy, and will not require replacement. Tubes 11 canbe readily replaced.

It will be seen that there is considerable elasticity allowed in someparts of the structure, as in the connections of shell-plates 2 21 totheir respective tube-sheets All small parts exposed to high temperaturecan be The boxes are preferably malleable castings. The shell-plates arepreferably rolled sheets of steel.

What we claim.is

1. A boiler consisting, essentially, of a top member composed ofconnected arched sections, a bottom member of sections arched in reversedirection, and downcasts at the rear connecting the two members andextending below the lower arches, thus forming a rear water-wall to thefurnace, substantially as described.

2. A steam-boiler consisting, essentially, of v a top member composed ofconnected arches, a bottom member composed of arches in reversedirections, tie plates connecting the curves formed by the junction ofthe arches to the transverse tube-sheets, and ties connecting these'tie-plates, and also the tubesheets, all combined substantially asdescribed.

3. A boiler-shell consisting, essentially, of a series of horizontalarches connected together side by side, the ends of said archesconsisting of a similar number of substantially vertical arches unitedat their edges to the horizontal arches, substantially as described.

4. The combination of the top arched sections connected at theinturnedangle to a tieplate, the bottom arches connected to a tieplate, and aconnection uniting the said tieplates to the top and bottom members,substantially as described.

5. The combination of the top arched memher, the bottom arched member,tube-sheets The tubes 36 areto which the arches are connected, and atieplate extending from one tube-sheet to the other, substantially asdescribed.

6. The combination with the top and bottom members having tube-sheetsfacing each other, a tie-plate between the tubesheets, and a refractoryprotective covering for said tieplate, substantially as described.

7. The combination of the top and bottom members, substantially asdescribed, tieplates connecting the same, a refractory cov- 4 ering forsaid tie-plates, and Water-tubes connecting the boiler members andbearing against the said refractory covering, substan tially as setforth.

8. The combination, with the arched shellplates, of ties connecting theedges of the top and bottom plates to open thimbles and tubes connectingsaid thimbles, substantially as described.

9. The top and bottom arched members, the tube-sheets facing each other,ties connecting the edges of the arches to open thimbles,

as described, and tie-tubes connecting the thimbles and passing throughand tied to the tube-sh eets, all the elements in combination,substantially as described.

10. In a steam-boiler, the combination of an outer shell composed ofconvolute sheets, tiepieces secured to the sheets at the lines of contraflexure, and ties joining these tiepieces from the opposite sides of theboiler, substantially as described.

11. In a steam-boiler of the character dcscribed, the combination, withan inturned arch-plate, of the flue-sheet secured thereto, one of saidplates having a corrugation near its edge to permit a slight elasticityand allow for expansion.

12. The combination, with the tube-sheet and the shell-plate, one of theplates having a corrugation near the joint, of a non-conducting packingfilling said corrugation, substantially as described.

13. The combination, with the inturned edges of the arched plates, as21, of a tieplate to which said arches are secured, a nonconducting orrefractory packing between the edges of the arches, and asupportingpiece for said packing, substantially as described.

14. The combination, with the top and bottom members, of the downcastconduits connecting the two and ashield inside the downcast, forming apartition separating that part next the fire from the main part of thedowncast.

15. The combination, with the downcasts, of deflecting curved shieldsinside the same and steam-pipes 26, extending through and above thedeflecting-shields.

16. The combination, with the arched top and bottom members anddowncasts connecting the arches of said members, of cross-tubesconnecting said downcasts, substantially as described.

17. The combination, with the top and bottom members, downcasts, andconnectingpipes, of the refractory covering resting on said pipes andsecured to said downcasts, substantially as described.

18. The top and bottom members, downcasts connecting the same, andcross-pipes and vertical pipes connecting said cross-pipes to the topmember, and a refractory covering or casing rest-ing against saidvertical pipes and downcasts, all combined substantially as described.

19. The combination of the upper and lower members and downcasts, therefractory casing between the downcasts, the outer covering of saidcasing, consisting of corrugated plates, and the angle-plates by whichsaid casing is secured to the downcasts, substantially as described.

20. The combination, with one of the boiler members and a box at theside thereof, of 'a tapering pipe extending nearly parallel with saidbox and connected to the main boiler-sections and to said box byvertical tubes, substantially as described.

21. The combination, with the arched boiler member, the box connectedtherewith, and vertical tubes leading to said box, of the downcast andbranch pipes 51, leading therefrom to said tubes, said pipes composed ofa tapering horseshoe-shaped trough, and a fiat flanged cap through whichthe vertical tubes pass, as set forth.

22'. The combination, with the arched bottom member, the boxes connectedthereto, and the downcast and branch pipes, of the vertical tubesconnecting said boxes and branch pipes and the refractory casing restingagainst said vertical tubes.

23. The combination, with the top and bottom members and verticalwater-tubes, of a jointed deflecting-plate in said top member,substantially as described.

24:. The steam-boiler described having a shell composed of continuousconvoluted plates disposed horizontally and vertically forming similararches, the concave faces of said arches being toward each other at top,bottom, and sides of the boiler, all secured together and tied in bybraces attached so as to draw tangentially on the curved surfaces.

In testimony whereof we affix our signatures in presence of twowitnesses.

NATHAN B. CLARK. FRANK B. KING. Witnesses:

WILLIAM W. BROWN, 'JOHN R. FARNUM.

